Along with the development of the radio network technology, a heterogeneous network (Heterogeneous Network, hereinafter referred to as HetNet) system has been proposed, and the heterogeneous network includes different radio networks, for example, a typical HetNet scenario is that there are a plurality of femtocell (Femto) base stations or picocell (Pico) base stations within the coverage range of a macro base station to provide a hot spot coverage. Generally, different base stations have different transmission powers and coverage ranges, a macro base station has a transmission power of tens of watts and a coverage radius of 500 m to 1000 m, which can be referred to as a high-power base station; and a base station with a relatively small transmission power and a relatively small coverage range can be referred to as a low-power base station, such as a Femto base station or a Pico base station, and the low-power base station has a relatively small transmission power and a relatively small coverage range, for example, a Femto base station generally has a coverage radius of about 10 m. Each base station can manage a plurality of cells, a cell managed by a macro base station is called a macro cell (Macro cell), a cell managed by a femto base station is called a femto cell (Femto cell), and a cell managed by a pico base station is called a pico cell (Pico cell). Each cell covers a certain range, which can serve a plurality of user equipments (User Equipment, hereinafter referred to as UE).
In a HetNet network, a low-power base station (such as a Femto base station or a Pico base station) is often within in the coverage range of a macro base station, and thereby a problem of strong interference at short range between the low-power base station and the macro base station may occur. If a unidirectional communication link from a base station to a UE is defined as a downlink and a unidirectional communication link from a UE to a base station is defined as an uplink, then there are mainly several types of strong interference as follows in the HetNet network: 1) in the downlink, the strong interference of a low-power base station on a UE served by the macro base station close to the low-power base station; 2) in the uplink, the strong interference of the UE served by the macro base station close to the low-power base station on the low-power base station.
The macro cell managed by a macro base station is mainly used to ensure cell coverage, while the low-power base station is mainly used to further improve system capacity. In the HetNet system, however, when a UE served by a macro base station approaches a low-power base station, because the signal of the macro cell is strong, the condition for UE enabling handover, measurement and reporting is not satisfied, thereby failing to realize the unloading of the UE served by the macro base station to the low-power base station.